Utilization of Al scrap for fabrication of Al(alloy)/Al2O3 composite material

Abstract

In status quo, Al scrap melt is diluted with pure Al and adjusted its composition for reuse. We studied a method to utilize Al scrap directly for fabricating composite materials, which can be used for machine elements having resistance to abrasion. The composite material is a product of displacement reaction between molten Al scrap and SiO2. Its microstructure consists of Al2O3 network and Al alloy among them. In this study, Al alloy was prepared which have a composition of Al scrap due to window frame of houses. The synthesized Al scrap are melted and reacted with SiO2 at 1473 K to obtain the composite material. The mechanical properties of this material were compared with Al/Al2O3 and (Al-Fe)/Al2O3 composite materials fabricated using pure Al, and Al-Fe alloy, respectively. It was demonstrated that the composite materials using scrap had a little higher strength and hardness than Al/Al2O3, and they were not broken into pieces upon fracture, as occurred in the case of (Al-10 at%Fe)/Al2O3. Further studies needed for application of this method was discussed. It was pointed out that the reactivity and the property change with compositional fluctuations of the scraps and reduction of the reaction temperature have to be taken into consideration.